Altyn and Waterton Formations

Altyn Formation: White to light gray dolomite interbedded with dolomitic sandstone and cross-bedded sandstone. Thickness as much as 800 m (2,625 ft). Waterton Formation: Gray to tan dolomite and dark gray limestone with chert nodules and minor dolomitic siltite and sandstone. Thickness 200 m (656 ft).
State Montana
Name Altyn and Waterton Formations
Geologic age Middle Proterozoic
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Carbonate > Dolostone (Bed)
Minor
Metamorphic > Metasedimentary > Metaclastic > Metasiltstonedolomitic siltite
Incidental
Sedimentary > Chemical > Chert (Bed)
References

Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2007, Geologic Map of Montana - Compact Disc: Montana Bureau of Mines and Geology: Geologic Map 62-C, 73 p., 2 sheets, scale 1:500,000. This map was digitized in 2012 as a result of a contract between the U.S. Geological Survey and the Montana Bureau of Mines and Geology.

NGMDB product
Counties Glacier